Piston lock



R. R. GRovER 2,632,425

PISTON LOCKv 2 SHEETS- SHEET 1 Attorney SQ. vm uw March 24, 1953 Filed may 26. 195o March 24, 1953' R. R. @ROVER 2,632,425

PIsToN Lows Filed May 2e. 195o 2 SHEETS-SHEET 2 Patented Mar. 24, 1953 PISTON LOCK Robert R. Grover, West Swanzey, N. H., assigner of one-half to Reginald L. Grover, West Svvanzey, N. H.

Application May 26, 1950, Serial No. 164,503

The present invention relates to piston locks and it consists in the combinations, constructions and arrangements of parts herein described and claimed. l

There isgenerally provided an elongated cylinder in which is reciprocally mounted a piston and piston rod of conventional character. Extending centrally and longitudinally from the inner side of the piston is a shaft having mounted a secondary piston at its outer end, thus providinga chamber between the main and secondary piston. A cylindrical separator is slidably mounted upon the shaft and divides the cham-` ber into what may be termed inner and outer compartments, the inner compartment being that adjacent the secondary piston. An integrally formed annular ring extends outwardly fromV the separator and into a circular locking sleeve. The extension is provided with a plu,- rality of openings, preferably three, ineach of which is mounted a steel ball. The locking sleeve is provided with a slight taper which is directed vinwardly and the balls are normally held against the tapered portion of the locking sleeve and against the shaft by means of a spring which surrounds the shaft and bears against the eXtension and against a portion of the locking sleeve. Meansis provided for the admissionof a fluid such as a liquid or gas through the side of the cylinder and thence through the locking sleeve whereby to move the principalpiston and the rod outwardly of the cylinder whereby to clamp or otherwise hold certain devices in clamped con.- dition. The locking means will then hold the device in such looked position after `the removal of the uid pressure. Means is also provided for the applicationv of pressure ag-ainstvthe secondary cylinder whereby toI release the locking means and permit the piston rod to move inwardly of the cylinder. In modified forms of the invention there is provided a spring loading means for the locking means whereby predetermined l-oads m-ay be placed upon the locking means.,

It is accordingly an object of the invention to provide a device of the character set forth which is comparatively simple in construction and op, leration and yet effective and efficient in use.

1 Claim. (Cl. 121-40) lil 2 I provision, in a device of the character set forth,` of novel means for placing Aa predetermined load upon a locking device forming a part of the in-j vention. i

Other and further objects of the invention lwill become apparent from a reading of the following specicationtaken in conjunction with Vthe drawings, in which:

Figure 1 is a vertical sectional view of an embodiment of the invention, i

lFigure 2 is a View similar to Figure l but showing Ka modification wherein a spring has been yadded thereto and which spring provides an additional predetermined load to the locking means shown therein,

Figure 3 is a View similar to Figure 1 but showing a modification wherein the piston rod extends through both ends of the cylinder whereby the device will be actuated in two directions;

Figure e is a view similar to Figure 3 but having the modification shown in Figure V2 added thereto,

Figure 5 is an elevational view of Va locking sleeve forming a part of theinvention,

Figure 6 is a sectional view taken along line 6--6 of Figure 5,

Figure 7 is an elevational `View of a chamber separator and ball race forming a part of the invention,

Figure 8 is a sectional view taken along line 8-3 of Figure 7,

Figure 9 is an elevational view of a secondary piston forming a part of the invention, and

Figure 10 is a sectional view taken along ,line I-IG of Figure 9.

Referring more particularly to the drawings, there is shown therein a cylinderv comprising a forward portion `IIB and a'rearward portion II each respectively provided with a ange I 2 and I3 which lianges are interconnected by means of bolts I4 or the like and which have interposed therebetween a sealing ring I5. y

A piston rod I6 extends through =a centrally disposed bushing I1 in the cylinder and isvsurrounded with a sealing ring I8 contained in a housing I9 in the outer end of the portion IQ of the cylinder. The inner end of the .piston rod I is aixed to a piston 20 having an annular groove 2l formed centrally in the outer walls thereof and in which groove is mounted a seal.

ing ring 22.

To the inner side of the piston 20 there 'is centrally affixed an extension rod 23 which extends inwardly through an opening 24 in a locking sleeve 25 and thence through a chamber sep'- -arator 26 and which has aflixed to its outer end a secondary piston 21 by means of a nut 23 and lock Washer 29. The piston 21 is provided with a sealing ring 30.

The locking sleeve 25 is xed in position substantially centrally within the cylinder by mounting the same in registering recesses Si formed in the inner walls of the portions It and I I, respectively', of the cylinder.

The separator 26 is provided with an outer sealing ring 32 which bears against the inner walls of the cylinder and an inner sealing ring 33 which bears against the sides of the extension rod 23. The separator 25` is likewise provided with a forwardly extending integrally formed ball race 34 which is provided with a series of openings 35 in each of which is mounted a ball 36:

The locking sleeve is provided with an inwardly extending annular front wall 31 and has formed in its outer periphery an annular groove 38 which is adapted to register with a radial pas-l sage 39 formed in the Vflange I2. A compressi-on spring 40 surrounds the extension rod 23 and bears against the wall 31 at one end and the ball race 34 at its other end.

That portion if the locking sleeve 25 which is remote from the wall 31 is provided with a rearwardly and inwardly tapering inner wall 4I. A passageway 42 extends radially through the flange I3 and communicates with the interiorA L* of the cylinder between the separator 25 and the secondary piston 21. 1 In the operation of this form of the invention, it will be apparent that as fluid under pressure enters the passageway 39 the same will then pass into the groove 38 and thence into the interior of the sleeve 25 through a radial passage 43 formed therein and will thence, because of the opening 24 impinge against the piston 23 and against the separator 26 to move the latter to f the right as viewed in Figure 1 of the drawings.

to perform desired work such as, for example.

the clamping of certain devices in selected positions, the lifting of platforms to desired heights, or the like.

vItwill valso be apparent that when pressure' upon the fluid entering the passageway 39 is re.- leased that the rod I6 will continue to perform its function and will remain in position due to the fact that any inward pressure upon the rod I5 will act to continue and even to increase the wedging action of the balls 36 between the extension rod 23 and the tapered surface 4I of the sleeve 25.

When, however, it is desired to again move the piston 20 and piston rod I6 to the right as viewed in Figure 1 ofl the drawings, it is only necessary to admit fluid under pressure into the passageway 42 whereupon the separator 26 will be moved to the left against the action of the spring 4l) thereby releasing the wedging action of the balls 36 between the extension 23 and tapered surface 4I and that further pressure upon the fluid entering. the passageway 42 will act to move the secondary piston 21 to the right to thus cause the inward movement of the rod I6 and its attached mechanisms.

In the form of the invention shown in Figure 2 of the drawings the construction is identical with that shown in Figure 1 and similar parts have been given identical reference characters. The difference in this form of the invention lies in the provisi-on of an elongatedball race 34a and the addition of a compression spring 44 having a predetermined strength and which spring surrounds the elongated portion 34a and bears against the sleeve 25 at one end and against a backing plate 45 at its other end. The backing plate 45 in.V turn bears against the inner end of a recess 45 in which the sleeve 25 is longitudinally slidable in the present form of the invention.

In the operation of this form of the invention, in addition to the functions above described with regard to Figure 1, it will be seen that the spring 44 places an additional and predetermined load upon the balls 35 in their coaction with the extension rod 23 and the tapered surface 4! so that locking sleeve 25 may not be released when pressure is brought to bear against. the secondary piston 21 and separator 25 until such pressure is great enough to overcome the strength opposed to it by the spring 44.

In the form of the invention shown in Figure 3 the construction is identical with that shown in Figure 1 with the exception that an intermediate body portion 41 is interposed between the flanges I2 and I3 and is connected to such flanges bybolts 48 and 43, respectively. r1`here is also provided an additional but oppositely acting locking means whose respective parts have each been designated by reference characters identical with those of the originally mentioned locking means but which reference. characters each bear the suiX a. There is valso provided a centrally disposed wall 50 within the body 41 through which the extension rod 23 slidably extends and which is provided with a sealing ring 5I which bears against the extension rod. The passageway 39 is provided with a connecting passageway 53 which in turn connects with a passageway 54 which communicates with a passageway 55 which, in turn, connects with a chamber 56 within the body 41 which chamber is bounded by the wall 5B and the separator 25a.

The passageway 42 is connected by a passage way 51 with a passageway 58 in the body 41 and this passageway is interconnected by a passagem way 59 which, in turn, leads to a chamber Eil formed in the body 41 and bounded by the separator 26 and the wall 55.

In the operation of this last described modification of the invention, it will be seen that, in addition to the functions ldescribed with regard to Figure 1 that when pressure is applied to the passageway 39k the sleeve 25a and balls 35d will be released from engagement with the extension rod 23 as the piston 20 is moved to the left, as viewed in the drawings and that, likewise, when pressure is applied to the passageway 42 that the locking sleeve 25, balls 3B and tapered walls 4I will become disengaged from the extension rod 23 as the piston 21a is moved positively to the right, as Viewed in the drawings.

With regard to the form of the invention shown in Figure Il, it will be seen that this construction is identical with that shown in Figure 3 but with the addition of recesses 33a and t! formed in the portions I EI and II of the cylinder and the elongated ball races 62| and 6,3 of the separators 26 and 26a, respectively. and the addition of compression springs 64 and 65 bearing against the sleeves 25 and 25a, respectively, at one of their ends and against backing plates 66 and 61 at their other ends.

In the operation of this last-mentioned form of the invention, it will be apparent that in addition to, the functions heretofore described with regard ,to Figure 3, that the springs 64 and 65 will function in the manner heretofore described with regard to Figure 2 of the drawings so that when the rod I 6 is moved in either direction that the locking means will not function to release the piston rod extension 23 until the predetermined strength of either of the springs E4 or 6,5 has rst been overcome.

While certain forms of the invention have been shown and described herein, it will be readily apparent/ to those skilled in the art that many minor Amodifications may be made without departing'.from the spirit of the invention or the scope of the appended claim.

What is claimed is: Y

A` device of the character described comprising a cylinder, a dividing wall centrally disposed in said vcylinder and forming the same into a rst and a second compartment, a piston in the first compartment, a piston rod affixed to the piston and extending outwardly through one end of the cylinder, a secondary piston in said second compartment, an extension rod interconnecting the piston and secondary piston and extending through said dividing wall, a rst locking sleeve surrounding the extension rod in said first compartment and having a frusto-conical inner wall tapering outwardly toward said piston, a cylindrical separator surrounding said extension rod withiny said first compartment, a ball race formed integrally with said separator and extending into the sleeve, balls in said race adapted to nterengage said extension rod and said frusto-conical inner wall when the separator and the sleeve are moved apart, a compression spring interposed between the sleeve and the race, a like sleeve reversely mounted in the second compartment, a like separator and ball race reversely mounted in the secondary compartment, balls mounted in said race and adapted to interengage said extension rod and said sleeve when the separator and the sleeve are moved apart, a compression spring interposed between the race and the sleeve, a conduit extending through the cylinder to a space therein dened by the dividing wall and the piston, a passageway in the walls of the cylinder interconnecting the said conduit and a space in the second compartment between the separator' and the dividing wall, a secondary conduit in said cylinder connecting with a space between the secondary piston and the reversely mounted separator, and a secondary passageway interconnecting the secondary conduit and a space in the first compartment defined by the dividing wall and the separator in said rst compartment.

ROBERT R. GROVER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,956,110 Turrettini 1 Apr. 24, 1934 2,205,346 Clench June 18, 1940 2,259,815 Greve Oct. 21, 1941 FOREIGN PATENTS Number Country Date 81,002 Austria July 26, 1920 829,975 France May 2, 1938 

